Sending Commands

Function

Sending Commands

URI

POST /v2/{project_id}/link/instances/{instance_id}/devices/{device_id}/send-command

**Table 1** Path Parameters
Parameter	Mandatory	Type	Description
project_id	Yes	String	Project ID. The default value is default for compatibility with 20.0.Project ID. For details about how to get the project ID, see "Appendix" > "Obtaining a Project ID" in this document.
instance_id	Yes	String	Instance ID. The default value is default for compatibility with 20.0.
device_id	Yes	Integer	Device ID.

Request Parameters

**Table 2** Request header parameters
Parameter	Mandatory	Type	Description
X-Auth-Token	Yes	String	User token, which can be obtained by calling the IAM API (value of X-Subject-Token in the response header).

**Table 3** Request body parameters
Parameter	Mandatory	Type	Description
service_id	Yes	Integer	Service ID. The value is automatically rounded down.
command_id	Yes	Integer	Command ID. The value is automatically rounded down.
is_sync	Yes	Boolean	Whether a command is synchronous.1: synchronous0: asynchronousIf the system sends a synchronous command to the device as an MQTT message, it waits for the MQTT response from the device (the timeout interval is 5 seconds by default) and then returns a response. If no response is received from the device within the timeout period, an error message is reported by the interface. If the system sends an asynchronous command to the device, it immediately returns a response without waiting for a response from the device.
is_cache_to_shadow	No	Boolean	Whether to save the command to the device shadow. 1 (default): yes; 0: no. If the command is saved in the device shadow, the device will receive it when it subscribes to the command topic or when a child device comes online. Once the command response is returned, the corresponding command is removed from the device shadow. If command storage in the device shadow is disabled, devices subscribed to the topic will not receive the command, even if delivery fails.
requests	No	Array of RequestParameter objects	Request parameter list.

**Table 4** RequestParameter
Parameter	Mandatory	Type	Description
parameter_name	No	String	Request parameter name.
parameter_value	No	String	Request parameter value.

Response Parameters

Status code: 400

**Table 5** Response body parameters
Parameter	Type	Description
error_code	String	System error code, which is the detailed error code of HTTP error codes 4xx and 5xx.
error_msg	String	Error description.
request_id	String	Message ID.

Status code: 404

**Table 6** Response body parameters
Parameter	Type	Description
error_code	String	System error code, which is the detailed error code of HTTP error codes 4xx and 5xx.
error_msg	String	Error description.
request_id	String	Message ID.

Status code: 500

**Table 7** Response body parameters
Parameter	Type	Description
error_code	String	System error code, which is the detailed error code of HTTP error codes 4xx and 5xx.
error_msg	String	Error description.
request_id	String	Message ID.

Example Requests

Send a synchronous command to a specified device.

{
  "service_id" : 10001,
  "command_id" : 20001,
  "is_sync" : 1
}

Example Responses

Status code: 400

Bad Request

{
  "error_code" : "SCB.00000000",
  "error_msg" : "Parameter is not valid for operation [romalink.link-device.sendCommand]. Parameter is [device_id]. Processor is [path].",
  "request_id" : "cb39e78a-afd3-4e04-901d-70468b1c23dc-1619602712496-cnnorth7a-P-romalink-service01"
}

Status code: 404

Not Found

{
  "error_code" : "ROMA.00110006",
  "error_msg" : "The resource does not exist. Check whether the resource ID 1 is correct.",
  "request_id" : "624c8be1-39b6-47b7-941d-c159aced368a-1619602544650-cnnorth7a-P-romalink-service01"
}

Status code: 500

Internal Server Error

{
  "error_code" : "ROMA.00110002",
  "error_msg" : "The instance does not exist. project_id: 397cd10b30544c588b2f4a56d83856c4, instance_id: f3bb386a-23ec-47aa-9943-4c60ac658611",
  "request_id" : "c8c06d0a-be92-4fdf-9d10-bc20131ab158-1619593104919-cnnorth7a-P-romalink-service01"
}